Phoenix to San Diego distance

Phoenix to San Diego by road

The fastest driving route is 355 miles (572 km) long and takes about 6 hr 35 min without stops or traffic. It runs mostly on I-8 (273 mi), AZ 85 (36.0 mi), and I-10 (30.8 mi).

It goes through 2 states: Arizona (185 mi) and California (170 mi). That’s an average of 54 mph (87 km/h). AAA recommends a break every two hours or 100 miles: with 3 stops of 20 minutes, the trip takes about 7 hr 35 min. The time is OSRM’s estimate with OpenStreetMap data: no traffic and speeds somewhat below the limits, so real trips can differ.

Straight-line distance and bearing

In a straight line, the shortest distance over the Earth’s surface, Phoenix and San Diego are 299 miles (481 km) apart. That’s the geodesic on the WGS84 ellipsoid, the distance “as the crow flies”.

The road is 19% longer: for every 100 miles in a straight line you drive 119. That’s a normal detour between two cities. Of the 110 US driving pairs in this series, it ranks 25th for detour (the average is 16%).

From Phoenix, San Diego lies to the west (bearing 262°), and from San Diego, Phoenix lies to the east. The straight line reaches San Diego on a bearing of 259°: on a sphere the bearing keeps changing along the way, which is why the shortest route looks slightly curved on a flat map.

Halfway between Phoenix and San Diego

Halfway along the straight line, 150 miles (241 km) from each city, is the point 33.1078° N, 114.6262° W. It falls near Martinez Lake (Arizona, pop. 89), 12.9 mi away. The nearest town of 20,000 people or more is Yuma (Arizona, pop. 105,227), 41.2 mi away.

By road, the halfway point is 178 miles (286 km) from each city, near El Prado Estates (Arizona, pop. 258), 1.9 mi away. The nearest town of 20,000 people or more is Yuma (Arizona, pop. 105,227), 11.1 mi away. The two midpoints are 30.3 mi apart: if you want to meet halfway, the one on the road is the useful one.

Time difference and flight

In winter, San Diego is 1 hour behind Phoenix; in summer, both share the same time. It changes because Arizona doesn’t observe daylight saving time.

No flight time is given: under 500 km (311 miles) in a straight line, time at the airport outweighs time in the air.

The two cities

Phoenix sits at 1,088 ft (332 m) and San Diego at 63 ft (19 m), 1,025 ft (312 m) lower.

Phoenix has 1.7 million people and San Diego 1.4 million people (Census Bureau estimate for 2025).